首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3495篇
  免费   29篇
  国内免费   10篇
安全科学   64篇
废物处理   239篇
环保管理   262篇
综合类   370篇
基础理论   707篇
环境理论   6篇
污染及防治   1314篇
评价与监测   331篇
社会与环境   231篇
灾害及防治   10篇
  2023年   43篇
  2022年   94篇
  2021年   143篇
  2020年   56篇
  2019年   59篇
  2018年   132篇
  2017年   133篇
  2016年   195篇
  2015年   102篇
  2014年   213篇
  2013年   332篇
  2012年   247篇
  2011年   253篇
  2010年   194篇
  2009年   122篇
  2008年   197篇
  2007年   228篇
  2006年   162篇
  2005年   136篇
  2004年   99篇
  2003年   81篇
  2002年   75篇
  2001年   44篇
  2000年   36篇
  1999年   22篇
  1998年   12篇
  1997年   9篇
  1996年   8篇
  1995年   14篇
  1994年   8篇
  1993年   5篇
  1992年   5篇
  1991年   4篇
  1990年   5篇
  1988年   2篇
  1985年   2篇
  1980年   2篇
  1978年   2篇
  1970年   2篇
  1967年   4篇
  1966年   4篇
  1965年   2篇
  1964年   5篇
  1962年   3篇
  1959年   4篇
  1958年   15篇
  1957年   5篇
  1955年   2篇
  1937年   1篇
  1928年   1篇
排序方式: 共有3534条查询结果,搜索用时 31 毫秒
981.
Aided phytostabilization is a technology that uses metal tolerant plants and organic and/or inorganic amendments to reduce soil metal bioavailability, while improving soil health. Our objective was to determine the effects of the application of amendments [sheep manure (SHEEP), poultry litter (POULTRY), cow slurry (COW), and paper mill sludge mixed with poultry litter (PAPER)], together with the growth of a metallicolous Festuca rubra L. population, on (i) chemical and microbial indicators of soil health and (ii) soil ecotoxicity, during the aided phytostabilization of a Zn/Pb contaminated mine soil. Amendment application led to an increase in soil pH, organic matter content, and inorganic salts, resulting in a decrease in Pb and Zn CaCl2-extractable concentrations in soil, which, in turn, contributed to lower ecotoxicity and a stimulation of plant growth and soil microbial communities. The factor most affecting the metal extractability was probably soil pH. POULTRY was the best amendment in terms of increasing plant growth, chlorophylls content, and soil microbial biomass and activity, but resulted in higher levels of phytoavailable Pb and Zn. SHEEP and PAPER were more effective at reducing metal CaCl2-extractability and, consequently, led to lower values of metal accumulation in plant tissues, thereby reducing the risk of metals entering into the food chain. When combined with the application of organic amendments, the metallicolous F. rubra population studied here appears an excellent candidate for aided phytostabilization. Our results indicate that the application of organic amendments is essential for the short-term recovery of highly contaminated metalliferous soils during aided phytostabilization.  相似文献   
982.
In the context of climatic temperature studies, more often than not a time series is affected by artificial inhomogeneities. To overcome such limitation, we propose a new simple methodology in which promising results point not only toward the detection of unknown inhomogeneous periods but also toward the possibility of reconstructing the uncertain portion of the series. It is based on a parsimonious statistical downscaling (Multiple Linear Regression) of the large-scale 20CR reanalysis data. This method is successfully applied upon two long-range temperature series from a couple of centennial observatories (Ebre and Fabra, NE of Spain) which do not have nearby suitable temperature series to compare with. Results of trend analysis point to a clear signal of warming, with a larger rate of increase for the maximum temperature (respect to the minimum one), for the more recent decades (respect to the whole available period), and for the original series (respect to the reconstructed ones).  相似文献   
983.
Coping with global environmental change demands new forms of civic engagement and interaction able to transform passive audiences attending to the drama of unsustainability into committed actors for sustainability. This entails linking diverse sources of scientific knowledge with personal experiences, emotion and ethical judgments. In this paper, we assess the potential as well as the limitations of innovative theatre-based participatory tools and methods aimed at supporting sustainability learning and agent transformation. To this aim, we first review a series of experiences using theatrical performance and introduce the notion of performative methods. Second, we assess to what extent these new approaches can be of relevance in environmental action research and sustainability science, practice and learning. Finally, we list a series of key research questions to further guide methodological innovation in this promising area of sustainability science and practice. Our findings show a growing and successful use of such methodologies worldwide, both in academia and in implementation-oriented approaches. An increasing number of topics and complexity is being embraced by these methods, offering a fertile ground for innovation in participatory sustainability science.  相似文献   
984.
Through a comparative analysis of prices in capture fisheries and aquaculture sectors, the objectives of this paper are a) to investigate three the trends in prices of forage catches to feed the aquaculture species, b) to analyze the amount of fish species need to feed aquaculture species in order to assess the level of efficiency in resource use, and c) to examine the degree of economic concentration either in wild-catch industry and aquaculture sectors. The results show that prices of cultivated species are higher than prices of the same species when harvested from the sea. We explain this fact by the interplay of three forces. First, the amount of wild fish to feed aquaculture species continues to improve over time. Second, the pressure of fishing activities has not been reduced since catches of most forage fishes are declining, which induce higher prices of capture species that feed aquaculture production. Third, the level of seafood market concentration is significantly higher in aquaculture than in wild catches, which generates higher prices in aquaculture.  相似文献   
985.
In this paper, we summarize the contributions made by an interdisciplinary group of researchers from different disciplines (biology, ecology, economics, and law) that deal with key dimensions of marine social–ecological systems. Particularly, the local and global seafood provision; the feasibility and management of marine protected areas; the use of marine ecosystem services; the institutional dimension in European fisheries, and the affordable models for providing scientific advice to small-scale fisheries. This Special Issue presents key findings from selected case studies around the world available to educators, policy makers, and the technical community. Together, these papers show that a range of diverse ecological, economic, social, and institutional components often mutually interact at spatial and temporal scales, which evidence that managing marine social–ecological systems needs a continuous adaptability to navigate into new governance systems.  相似文献   
986.
987.
This study reports a combined method using solid phase extraction (SPE), followed by solid phase microextraction (SPME) to concentrate different pesticides, including chlorinated, organophosphorus, triazines, pyretroids and chloroacetamides, present at trace levels in water samples. Identification and quantification was carried out by gas chromatography coupled to Mass Spectrometry (GC–MS). The optimized methodology showed LOQs at ng L?1 levels (ranging 0.2–3.5 ng L?1) in addition to acceptable precision and robustness (recoveries ranged 63–104%, RSD from 4% to 23%), presenting a novel method to reach trace levels, similar to that obtainable using EC detector, with structural confirmation by MS during the analysis of a wide range of environmental pollutants.This method was applied to the study of temporal and spatial distribution of pesticides in the Suquía River basin (Córdoba-Argentina). As expected, highest levels of agrochemicals were observed in areas with intensive agricultural practices, being atrazine (max. = 433.9 ng L?1), alpha-cypermetrine (max. = 121.7 ng L?1) and endosulfan sulfate (max. = 106.7 ng L?1) predominant. In urban areas, the prevalent pesticide was alpha-cypermethrine. These results draw attention to the need of pesticide monitoring programs in rivers, considering both urban and rural sections.  相似文献   
988.
Persistent organic pollutants (POPs) are within the most dangerous pollutants released into the environment by human activities. Due to their resistance to degradation (chemical, biological or photolytic), it is critical to assess the fate and environmental hazards of the exchange of POPs between different environmental media.System Dynamics enables to represent complex systems and analyze their dynamic behavior. It provides a highly visual representation of the structure of the system and the existing relationships between the several parameters and variables, facilitating the understanding of the behavior of the system. In the present study the fate of γ-hexachlorocyclohexane (lindane) in a contaminated soil was modeled using the Vensim® simulation software.Results show a gradual decrease in the lindane content in the soil during a simulation period of 10 years. The most important route affecting the concentrations of the contaminant was the biochemical degradation, followed by infiltration and hydrodynamic dispersion. The model appeared to be highly sensitive to the half-life of the pollutant, which value depends on environmental conditions and directly affects the biochemical degradation.  相似文献   
989.
The aim of this study was to assess the effectiveness of combining liming and vegetation for the phytomanagement of strongly acidic, saline eutrophic wetlands polluted by mine wastes. Simulated soil profiles were constructed and four treatments were assayed: without liming + without plant, without liming + with plant, with liming + without plant and with liming + with plant. The plant species was the halophyte Sarcocornia fruticosa. Three horizons were differentiated: A (never under water), C1 (alternating flooding–drying conditions) and C2 (always under water). The soluble Cd, Cu, Mn, Pb and Zn concentrations were measured regularly for 18 weeks and a sequential extraction procedure was applied at the end of the experiment. Liming was effective (between ~70% and ~100%) in reducing the soluble Zn, Cu and Pb. In contrast, soluble Mn and Cd increased with liming, especially in the treatment with liming + with plant, where the concentrations were 2-fold higher than in the non-limed treatments. The amendment increased the contents of Zn, Mn and Cd bound to potentially-mobilisable soil fractions at the expense of the most-environmentally-inert fractions. Hence, the combined use of liming and vegetation may increase the long-term environmental risk of metals solubilisation.  相似文献   
990.
The aim of this study was to investigate the in vitro effect of an antifungal fraction obtained from Jacquinia macrocarpa plant (JmAF) in the generation of reactive oxygen species (ROS) and the activity of the catalase (CAT) and superoxide dismutase (SOD) enzymes from Fusarium verticillioides, as well as their influence in the viability of the fungus spores. The compounds present in the JmAF were determined by gas chromatography/quadrupole time-of-flight mass spectrometry (GC/QTOF-MS). The effect of the exposition to JmAF on the generation of ROS, as well as in the CAT and SOD activities in F. verticillioides, was determined. The main compounds detected were γ-sitosterol, stephamiersine, betulinol and oleic acid. JmAF showed very high ability in inhibiting the spore viability of F. verticillioides, and their capacity to cause oxidative stress by induction of ROS production. JmAF induced the highest ROS concentration and also inhibited CAT and SOD activities. The results obtained in this study indicate that JmAF is worthy of being considered for the fight against phytopathogenic fungi.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号